Production of metal components by grinding



March 17, 1942. F. W.IWH'ITEHEAD ETAL 2,276,904

PRODUCTION OF METAL- COMPONENTS BY GRINDING Filed Jan. 19, 1940 5 Sheets-Sheet 1 five/750229: 7 40M 2% M PRODUCTION OF METAL COMPONENTS BY GRINDL ING 5 Sheets-Sheet 2 Filed Jan. 19, 1940 Mvrmfors:

March 17, 1942. F, w. WHITEHEAD ETAL 2,275,904

PRODUCTION OF METAL COMPONENTS BY GRINDING I Filed Jan. 19, 1940 5 Sheets-Sheet s ,5: mmiors March 17, 1942.

F. w. WH'ITEHEAD ET AL 2,276,904

PRODUCTIONDF METAL COMPONENTS BY GRINDING Fil'ed Jan. 19, 1940 5 Sheets-Sheet 4 FIG. 4.

Miirch 1942. F. w. WHlT-EHEAD EIAL PRODUCTION OF METAL COMPONENTS BY GRINDING File'd Jan. 19, 1940 5 Sheets-Sheet 5 Patented Mar. 17, 1942 PRODUCTION OF METAL COMPONENTS B GRINDING Frederick William Whitehead, Bristol, and Stanley J affa Harley, Coventry, England Application January 19, 1940, Serial No. 314,716 In Great Britain February 1, 1939 14 Claims.

The object of the present invention is to provide for the economic production of such screwthreaded metal components as are capable of being produced or finished by a grinding operation, the present methods of individual grinding being found to be inadequate to meet the rapidly growing demand.

According to the present invention the production or finishing of screw-threaded metal components by a grinding operation is very considerably increased by a method of multiple grinding in which a number of work-pieces are simultaneously rotated in contact with a suitably formed grinding wheel while a relative traversing motion takes place between the latter and the said work pieces. I

The invention involves the provision in a screw-threaded grinding machine of a workhead in which a plurality of rotatable workcarriers are arranged around the operative surface of a suitably formed grinding wheel and are adapted to be moved to bring the work-pieces into simultaneous and equal contact therewith. The said work-carriers are all adapted to be rotated in the same direction and at the same speed and for this purpose may each be provided with a driving pinion. All the driving pinions can be driven from a common driving member through idler pinions in constant mesh with each pair of adjacent pinions, or in any other suitable manner.

In the accompanying drawings:

Figure 1 is a view in side elevation of the complete multiple screw-thread grinding attachment.

Figure 2 is an end View of the headstock as seen from the right hand of Figure 1.

Figure 3 is an end view of the tailstock as seen from the left hand of Figure 1. Y

Figure 4 is a view similar to Figure 2 illustrating an alternative method for the simultaneous rotation of the work-pieces.

Figure 5 is a view similar to Figure 4 illustrating more or less diagrammatically another method for the simultaneous rotation of the work-pieces.

Figure 6 illustrates a grinding wheel of the single annular ribbed type.

Figure 7 illustrates a grinding wheel of the multiple helical ribbed type.

Figure 8 is a side elevation of the head stock shown in Figure 1 illustrating the mechanism employed for producing relative movements of translation between the grinding wheel and the work head.

Referring to the drawings the multiple grinding attachment consists of a work-head comprising head and tail stocks 2, 3 secured to a base member 4 adapted for'attachment to a slide 5 which is arranged to have a traversing motion along the bed of the machine across the operative surface of the grinding wheel 6. The traversing motion of the slide can be produced by means of a lead screw or in any other manner usually employed on grinding machines.

In the construction shown in Figures 1, 2 and 3. the head and tail stocks 2, 3 which are secured by the base members 4 to the slide 5 by the bolts 1, are each provided with a series of four work centres 8 which are arranged with their axes parallel with each other and with the axis of the grinding wheel '6. The two inner centres in each case are fixed relatively to each other and to the axis of the grinding wheel but the outer centres are simultaneously adjustable towards and away from the grinding wheel. For this purpose the said outer centres are carried by slides 9 which are adjustable on the head and tail stocks towards and away from the grinding wheel by means of screws l0 working in nuts ll fixed to the head and tail stocks and carrying calibrated dials I2 which are rotatable relatively to fixed marks 13 on the head and tail stocks. Any suitable type of locking device may be employed to secure the slides in their adjusted positions. The. locking devices for this purpose shown in Figure 1 comprise screws l4 working in nuts IS in the slides 9 and carrying clamping members l6 adapted to engage the guides I! on the head and tail stocks. A handle M is provided on each of the screws M for manipulation.

To facilitate mounting the work-pieces 18 in position for the grinding operation the centres in the tail stock can each be independently withdrawn against the action of a spring 19 by'means of a handle 20 at the outer end. In their operative position'seach of these centres are locked by means of spring loaded friction blocks 2i bearing upon the centres and. operated by means. of screws 22 having handles 23 at their outer ends.

For rotating the work-pieces each of the centres in the headstock is provided with' a pinion 24 loosely mounted thereon and having a sleeve extension carrying a driving collar 25.

Each work-piece is fitted with a driving dog 26 which is driven by a driving peg 21 on the drivingspeeds in the same direction.

The two inner pinions are both driven direct from a central pinion 28 keyed to a spindle 29 which is rotatably mounted in the headstock in operative driven relationship with a driving shaft. In the example shown the direction of rotation of the driving shaft is reversed by means of the bevel gear 30 shown.

The outer pinions are driven from the inner pinions by means of idler pinions 3| carried by links 32 pivoted about the axes of the inner and outer pinions. By means of this arrangement the speed and direction of rotation of the outer pinions is the same as that of the inner pinions whilst the linkage allows for adjustment of the outer pinions towards and away from the grinding Wheel relatively to the inner pinions without interrupting the drive.

The tailstock is adjustable on the base member towards and away from the headstock, according to the length of the work-piece, and is secured in its adjusted position by means of a bolt 33. The head-stock is secured on said base member by bolts 34.

In the alternative arrangement shown in Figure 4 the pinions are driven in a different way. In this case each pinion is driven in the same direction and at equal speeds independently by means of Worms 35 in constant mesh with worm teeth on the pinions. The several worm shafts are all driven by worm gear 33 from a common worm shaft 31. In this case the inner pinions are carried by a slide 9 which is adjustable in the headstock towards and away from the grinding wheel by means of an adjusting screw l, rotatably mounted in the headstock and working in a nut H fixed to the slide. The adjusting screw is provided with a calibrated dial I2 and locking device in a manner similar to that above described.

Instead of employing a separate worm spindle for each pinion each pair of the latter may, as shown in Figure 5, be driven simultaneously in the same direction and at equal speeds by means of a worm shaft 38 common to each pair of pinions and carrying right and left hand worms 39 meshing with worm teeth on the pinions. The two worm spindles can both be driven simultaneously and at equal speeds by means of a common worm shaft 40. By making the worms on the spindles of suflicient length the work centres carrying the pinions can be adjusted relatively to each other in the direction of the grinding wheel in either of the ways herein described with reference to Figures 1 and 4, that is to say, the outer centres may be made adjustable relatively to the inner centres, or vice versa.

As previously stated, the traversing motion of the slide may be produced by means of a lead screw, and an arrangement for this purpose is illustrated in Figure 8. A casing 4| is mounted on the slide together with the head and tail stocks 2, 3 and an electric motor 42 carried by said casing 4| provides the motive power for the traversing motion and for rotating the work pieces. The motor 42 drives a vertical shaft 43 which transmits the drive through worm gearing 44 and spiral gears 45 to a horizontal shaft 46. One end 45 of the shaft 46 is coupled to the driving shaft of the bevel gears 30 which transmit the drive to the work pieces as previously described. The other end of the shaft 46 is operatively connected with gear trains 4T, 48 which transmit the drive to a lead screw 49. A bearing 50 carried by the slide 5 supports the lead screw 49 so that the latter is free to rotate but not to move axially therein. A nut 5i secured on the machine bed 52 is engaged by the lead screw so that as the latter is rotated it will move axially with respect to the machine bed due to the coaction with the nut and traverse with it the slide 5 together with the members mounted thereon.

In operation the work pieces I 8 are mounted between the work centres 8 on the head and tail stocks 2, 3 and are adjusted into position for operation thereon by the grinding Wheel 6 by means of the screw and nut gear l6, H or I0, I I as previously described. The grinding wheel is then rotated by any convenient means, and the work pieces are rotated and the lead screw 49 operated to traverse the work pieces across the face of the grinding wheel, by means of the drive from the electric motor 42. At the end of the traverse, the drives are disconnected or stopped, the work pieces removed, and fresh ones may then be inserted preparatory to a succeeding operation.

The improved method of and means for multiple grinding herein described is particularly though not exclusively intended for use in the production of screw-threaded members, such as studs, bolts, screws and the like in which case the grinding wheel may be of the single or multiple annular or helical rib types as shown in Figures 6 and 7 wherein the wheel is indicated by the reference numerals 6!! and 63 respectively.

The improved work-head may be applied to any appropriate type of grinding machine having one or more rotatable grinding wheels.

We claim:

1. A work head for grinding machines employing a rotary grinding wheel comprising, a slide mounted adjacent said grinding wheel for linear movement in a direction parallel to the axis thereof, a lead screw for producing such linear movement, head and tail stocks carried by said slide, said head stock and said tail stock each comprising a member fixedly attached to said slide for linear movement therewith and a sliding member mounted on said fixedly attached member for sliding adjustment perpendicular to the axis of said grinding wheel, a pair of outer work centres mounted on each said sliding member, and a pair of inner work centres mounted on each said fixedly attached member for relative movement between the outer centres of its corresponding sliding member, the respective work centres of said head and tail stocks being in respective axial alignment and having their axes parallel to each other and to the grinding wheel axis, and means associated with the work centres of the head stock for producing a simultaneous equal amount of rotation in the same direction of the respective work pieces carried thereby in all operative positions of said centres.

2. A work head for grinding machines employing a rotary grinding wheel comprising a slide mounted adjacent said grinding wheel for linear movement in a direction parallel to the axis thereof, means for producing such movement, head and tail stocks carried by said slide, said head stock and said tail stock each comprising a member fixedly attached to said slide for linear movement therewith, and a sliding member mounted on said fixedly attached member for sliding adjustment perpendicular to the axis of said grinding wheel, a pair of outer work centres mounted on each said sliding member, and a pair of inner work centres mounted on each said fixedly attached member for relative movement between the outer centres of its cooperating sliding member, the respective work centres of said head and tail stocks being in axial alignment and having their axes parallel to the grinding wheel axis.

3. A workhead for grinding machines employing a rotary grinding wheel comprising a slide mounted adjacent said grinding wheel for linear movement parallel to the axis thereof, means for producing such linear movement, and head and tail stocks carried by said slide, in combination with a pair of inner relatively spaced work centres mounted on each said stock, a pair of outer relatively spaced work centres mounted on each said stock, the outer and inner pair of centres of each said stock being relatively adjustable in a direction perpendicular to the axis of said grinding wheel, the respective inner and outer centres of said head and tail stocks being in axial alignment with their axes parallel to the grinding wheel axis, and means associated with the work centres of one of said stocks for thereon in all operative positions of said centres.

4. A work head for grinding machines employing a rotary grinding wheel comprising, a slide mounted adjacent said grinding wheel for linear movement parallel to the axis thereof, and head and tail stocks carried by said slide, in combination with a pair of inner relatively fixedly spaced work centres mounted on each said stock, a pair of outer relatively fixedly spaced work centres mounted on each said stock, the respective outer and inner pairs of centres of each said stock being relatively adjustablein a direction perpendicular to the axis of the grinding wheel, and the respective centres of each said stock being disposed symmetrically on either side of the grinding wheel axis.

5. A headstock for grinding machines employing a rotary grinding wheel comprising a supporting member disposed adjacent the grinding wheel for movement parallel to the axis thereof, a transversely sliding member carried by said first mentioned member for linear movement perpendicular to the axis of said grinding wheel, a pair of relatively fixedly spaced outer work centres carried by said sliding member and disposed symmetrically on opposite sides of the axis of said grinding wheel, and a pair of relatively fixedly spaced inner work centres carried by said supporting member and symmetrically disposed on opposite sides of the grinding wheel axis for relative movement between said outer centres during sliding movement of said sliding member, the axes of all of said centres being parallel to the grinding wheel axis, in combination with means for producing simultaneous equal rotation of the work pieces supported on said respective centres in all operative positions of said members.

6. A headstock for grinding machines employing a rotary grinding wheel comprising, a supporting member disposed adjacent the grinding wheel for movement parallel to the axis thereof, a transversely sliding member carried by said supporting member for linear adjustment perpendicular to the axis of said grinding wheel, a pair of relatively fixedly spaced outer work centres carried by said sliding member and disposed symmetrically on opposite sides of the grinding wheel axis, and a pair of relatively fixedly spaced inner work centres carried by said supporting member and symmetrically disposed on opposite sides of the grinding wheel axis for relative movement between said outer centres during adjustment of said sliding member, the axes of all of said centres being parallel to the grinding Wheel axis, in combination with means for producing simultaneous equal rotation of the Work pieces supported on said respective centres in all operative positions of said members, comprising driven pinions mounted for rotation on each of said centres, work piece engaging means operatively connected to each said pinion for rotation therewith, link supported idler pinions mounted between and in mesh with the driven pinions of each adjacent pair of inner and outer centres, and a drive pinion disposed between and in mesh with the respective driven pinions of said inner centres.

7. A headstock for grinding machines employing a rotary grinding wheel comprising, a supporting member disposed adjacent the grinding wheel for movement parallel to the axis thereof, a transversely sliding member carried by said supporting member for adjustment perpendicular to the axis of said grinding wheel, a pair of relatively fixedly spaced outer work centres carried by said sliding member and disposed symmetrically on opposite sides of the grinding wheel axis, and a pair of relatively fixedly spaced inner work centres carried by said supporting member and symmetrically disposed on opposite sides of the grinding wheel axis for relative movement between the said outer centres during adjustment of said sliding member, the axes of all of said centres being parallel to the grinding wheel axis, in combination with means for producing simultaneous equal rotation of the work pieces supported on said respective centres in all operative positions of said members, comprising driven pinions mounted for rotation on each of said centres, work piece engaging means operatively connected to each said pinion for rotation therewith, driving worms in mesh with each of said driven pinions, and means for rotating each of said worms.

8. A headstock for grinding machines employing a rotary grinding wheel comprising, a supporting member disposed adjacent said grinding wheel, a transversely slidable member carried by said supporting member for linear adjustment perpendicular to the axis of said grinding wheel, a pair of relatively fixedly spaced outer work centres carried by one of said members, and a pair of relatively fixedly spaced inner Work centres carried by the other of said members, in combination with means associated with said centres for producing simultaneous rotation of the work pieces supported thereon in all operative positions of said members.

9. A headstock for grinding machines employing a rotary grinding wheel comprising, a supporting member disposed adjacent said grinding wheel, a transversely slidable member carried by said supporting member for linear adjustment perpendicular to the axis of said grinding wheel, a pair of relatively fixedly spaced outer work centres carried by one of said members, and a pair of relatively fixedly spaced inner work centres carried by the other of said members.

10. A headstock for grinding machines employing a rotary grinding wheel comprising a supporting member disposed adjacent said grinding wheel, a transversely slidable member carried by said supporting member for sliding movement relative thereto in a direction perpendicular to the axis of said grinding wheel, and relatively symmetrically disposed work centres carried by said respective members.

11. A work head for a screw thread grinding machine employing a rotary grinding wheel comprising, a slide mounted adjacent said grinding wheel for linear traversing movement parallel to the axis thereof, traversing mechanism for producing such movement, head and tail stocks carried by said slide, said head stock and said tail stock each comprising a member normally fixedly attached to said slide for movement therewith, and a sliding member mounted on said fixedly attached member for sliding adjustment relative thereto in a direction perpendicular to the grinding wheel axis, a pair'of outer work centres carried by one of said members, and a pair of inner work centres carried by the other of said members, and means associated with the work centres of said head stock and with said traversing mechanism for causing a simultaneous equal amount of rotation of the work pieces carried by said centres at a fixed rate of speed relative to the rate of linear traversing movement thereof in all adjusted positions of said centres.

12. A work head for a screw thread grinding machine employing a rotary grinding wheel comprising, a slide mounted adjacent said grinding wheel for linear traversing movement parallel to the axis thereof, traversing mechanism for producing such linear movement, head and tail stocks carried by said slide, a pair of relatively fixedly spaced outer work centres carried by each said stock and disposed symmetrically on opposite sides of the grinding wheel axis, and a pair of relatively fixedly spaced inner work centres carried by each said stock and disposed symmetrically on opposite sides of the grinding wheel axis, said inner and outer pairs of work centres of each said stock being adjustable relative to each other in a direction perpendicular to the grinding wheel axis, in combination with mechanism associated with the work centres of one of said stocks and with said traversing mechanism for causing a simultaneous equal amount of rotation of the work pieces carried by all of said centres at a fixed rate of speed relative to the rate of traversing movement of said slide in all adjusted positions of said centres.

13. A work head for a screw thread grinding machine employing a rotary grinding wheel comprising, a slide mounted adjacent said grinding wheel, traversing mechanism for causing a relato the rotational axis of said grinding 'wheel, work positioning means carried by said slide for presenting a plurality of work pieces to the circumferential face of the grinding wheel respectively at different points about the circumference of the latter, said means including a pair of relatively fixedly spaced inner work supporting members disposed symmetrically on opposite sides of the grinding wheel axis, a pair of relatively fixedly spaced outer work supporting members disposed symmetrically on opposite sides of the grinding wheel axis, said inner and outer pairs of members being adjustable relative to each other in a direction perpendicular to the grinding wheel axis, and means for supporting said members on said slide, in combination with mechanism for causing a simultaneous equal amount of rotation of the work pieces carried by all of said work supporting members at a fixed rate of speed relative to the rate of relative traversing movement between said slide and said grinding wheel in all adjusted positions of said members.

14. A work head for a screw thread grinding machine employing a rotary grinding wheel and operating simultaneously upon a plurality of work pieces, comprising positioning means for presenting a plurality of cylindrical work pieces to the circumferential face of the grinding wheel at different points about the circumference of the latter with the axes of said work pieces disposed parallel to each other and to the grinding wheel axis, means for bodily adjusting said positioning means and the work pieces carried thereby relative to each other in a direction perpendicular to the axis of said grinding wheel to compensate for wear on the latter while at the same time maintaining said work pieces parallel to each other and to the grinding wheel axis, supporting means for said positioning means, means for individually rotating all of said work pieces simultaneously in any adjusted relation thereof, and means for moving said supporting means together with said positioning means and said work pieces parallel to the axis of said grinding wheel to traverse said work pieces across the face of said grinding wheel at a predetermined rate of linear movement with relation to the speed of rotation of the individual work pieces.

STANLEY JAFFA HARLEY. FREDERICK WILLIAM WHITEHEAD. 

